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path: root/drivers/i2c/busses/i2c-sh_mobile.c
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-rw-r--r--drivers/i2c/busses/i2c-sh_mobile.c121
1 files changed, 44 insertions, 77 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index a64f2ff3cb49..8777af4c695e 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -2,8 +2,7 @@
/*
* SuperH Mobile I2C Controller
*
- * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
- *
+ * Copyright (C) 2014-19 Wolfram Sang <wsa@sang-engineering.com>
* Copyright (C) 2008 Magnus Damm
*
* Portions of the code based on out-of-tree driver i2c-sh7343.c
@@ -303,13 +302,12 @@ static int sh_mobile_i2c_v2_init(struct sh_mobile_i2c_data *pd)
return sh_mobile_i2c_check_timing(pd);
}
-static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
- enum sh_mobile_i2c_op op, unsigned char data)
+static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op op)
{
unsigned char ret = 0;
unsigned long flags;
- dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
+ dev_dbg(pd->dev, "op %d\n", op);
spin_lock_irqsave(&pd->lock, flags);
@@ -317,12 +315,12 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
case OP_START: /* issue start and trigger DTE interrupt */
iic_wr(pd, ICCR, ICCR_ICE | ICCR_TRS | ICCR_BBSY);
break;
- case OP_TX_FIRST: /* disable DTE interrupt and write data */
+ case OP_TX_FIRST: /* disable DTE interrupt and write client address */
iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
- iic_wr(pd, ICDR, data);
+ iic_wr(pd, ICDR, i2c_8bit_addr_from_msg(pd->msg));
break;
case OP_TX: /* write data */
- iic_wr(pd, ICDR, data);
+ iic_wr(pd, ICDR, pd->msg->buf[pd->pos]);
break;
case OP_TX_STOP: /* issue a stop (or rep_start) */
iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
@@ -353,34 +351,17 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
return ret;
}
-static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
-{
- return pd->pos == -1;
-}
-
-static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
- unsigned char *buf)
-{
- switch (pd->pos) {
- case -1:
- *buf = i2c_8bit_addr_from_msg(pd->msg);
- break;
- default:
- *buf = pd->msg->buf[pd->pos];
- }
-}
-
static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
{
- unsigned char data;
-
if (pd->pos == pd->msg->len) {
- i2c_op(pd, OP_TX_STOP, 0);
+ i2c_op(pd, OP_TX_STOP);
return 1;
}
- sh_mobile_i2c_get_data(pd, &data);
- i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, data);
+ if (pd->pos == -1)
+ i2c_op(pd, OP_TX_FIRST);
+ else
+ i2c_op(pd, OP_TX);
pd->pos++;
return 0;
@@ -391,45 +372,32 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
unsigned char data;
int real_pos;
- do {
- if (pd->pos <= -1) {
- sh_mobile_i2c_get_data(pd, &data);
-
- if (sh_mobile_i2c_is_first_byte(pd))
- i2c_op(pd, OP_TX_FIRST, data);
- else
- i2c_op(pd, OP_TX, data);
- break;
- }
-
- if (pd->pos == 0) {
- i2c_op(pd, OP_TX_TO_RX, 0);
- break;
- }
-
- real_pos = pd->pos - 2;
-
- if (pd->pos == pd->msg->len) {
- if (pd->stop_after_dma) {
- /* Simulate PIO end condition after DMA transfer */
- i2c_op(pd, OP_RX_STOP, 0);
- pd->pos++;
- break;
- }
-
- if (real_pos < 0) {
- i2c_op(pd, OP_RX_STOP, 0);
- break;
- }
- data = i2c_op(pd, OP_RX_STOP_DATA, 0);
- } else if (real_pos >= 0) {
- data = i2c_op(pd, OP_RX, 0);
+ /* switch from TX (address) to RX (data) adds two interrupts */
+ real_pos = pd->pos - 2;
+
+ if (pd->pos == -1) {
+ i2c_op(pd, OP_TX_FIRST);
+ } else if (pd->pos == 0) {
+ i2c_op(pd, OP_TX_TO_RX);
+ } else if (pd->pos == pd->msg->len) {
+ if (pd->stop_after_dma) {
+ /* Simulate PIO end condition after DMA transfer */
+ i2c_op(pd, OP_RX_STOP);
+ pd->pos++;
+ goto done;
}
- if (real_pos >= 0)
- pd->msg->buf[real_pos] = data;
- } while (0);
+ if (real_pos < 0)
+ i2c_op(pd, OP_RX_STOP);
+ else
+ data = i2c_op(pd, OP_RX_STOP_DATA);
+ } else if (real_pos >= 0) {
+ data = i2c_op(pd, OP_RX);
+ }
+ if (real_pos >= 0)
+ pd->msg->buf[real_pos] = data;
+ done:
pd->pos++;
return pd->pos == (pd->msg->len + 2);
}
@@ -698,7 +666,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
start_ch(pd, msg, do_start);
if (do_start)
- i2c_op(pd, OP_START, 0);
+ i2c_op(pd, OP_START);
/* The interrupt handler takes care of the rest... */
timeout = wait_event_timeout(pd->wait,
@@ -749,8 +717,7 @@ static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
};
/*
- * r8a7740 chip has lasting errata on I2C I/O pad reset.
- * this is work-around for it.
+ * r8a7740 has an errata regarding I2C I/O pad reset needing this workaround.
*/
static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
{
@@ -802,15 +769,15 @@ static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
{ .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config },
{ .compatible = "renesas,iic-r8a774c0", .data = &fast_clock_dt_config },
{ .compatible = "renesas,iic-r8a7790", .data = &v2_freq_calc_dt_config },
- { .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
- { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
- { .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config },
- { .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config },
- { .compatible = "renesas,rcar-gen2-iic", .data = &fast_clock_dt_config },
- { .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config },
- { .compatible = "renesas,rcar-gen3-iic", .data = &fast_clock_dt_config },
- { .compatible = "renesas,iic-r8a77990", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7791", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,iic-r8a7792", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,iic-r8a7793", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,iic-r8a7794", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,iic-r8a7795", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,iic-r8a77990", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,rcar-gen2-iic", .data = &v2_freq_calc_dt_config },
+ { .compatible = "renesas,rcar-gen3-iic", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
{},
};
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.